5272-36-6Relevant articles and documents
Synthesis of cyclic polyelectrolyte via direct copper(I)-catalyzed click cyclization
Chen, Fenggui,Liu, Guangming,Zhang, Guangzhao
, p. 831 - 835 (2012)
Well-defined cyclic poly(acrylic acid) (PAA) has been successfully prepared based on the direct click cyclization. The linear poly(tert-butyl acrylate) (PtBA) with azide and TMS-protected alkyne group forms cyclic chain directly by the copper(I)-catalyzed click cyclization without any deprotection steps. Cyclic PAA is synthesized by the hydrolysis of cyclic PtBA. The present synthetic strategy provides a simple and efficient method to synthesize cyclic polyelectrolyte and can be applied to other polymer systems. Copyright
DICOBALTOCTACARBONYL-ALKYNE COMPLEXES AS INTERMEDIATES IN THE SYNTHESIS OF BICYCLOOCTENONES FOR THE SYNTHESIS OF CORIOLIN AND HIRSUTIC ACID
Magnus, Philip,Exon, Christopher,Albaugh-Robertson, Pamela
, p. 5861 - 5869 (1985)
Treatment of the readily prepared enzynes 12, 21 and 45 with Co2(CO)8 at ca 110 deg C results in high yields (80percent) of substituted bicyclooctenones, that are suitable for straightforward elaboration into coriolin and hirsutic acid precursors.A mechanistic hypothesis to explain the observed stereospecificity is presented.
Silver-catalyzed heterocyclization: First total synthesis of the naturally occurring cis 2-hexadecyl-3-hydroxy-4-methylene butyrolactone
Dalla,Pale
, p. 3525 - 3528 (1994)
The title compound was obtained in 4 steps with an overall yield of 64% with the silver-catalyzed cyclization of the corresponding substituted β-hydroxy-γ-acetylenic acid as the key step.
An unusual rearrangement of 1-trimethylsiloxy-3-bromomagnesium-2-propyne
Medvedeva,Novokshonov,Demina,Voronkov
, p. 481 - 482 (1998)
3-Trimethylsilyl-2-propyn-1-ol (4) was synthesized via the rearrangement of 1-trimethylsiloxy-3-bromomagnesium-2-propyne and followed by hydrolysis of the latter. The yield of compound 4 depends largely on the solvent used.
Skeletal Optimization of Cytotoxic Lipidic Dialkynylcarbinols
Bourkhis, Maroua,Gaspard, Hafida,Rullière, Pauline,de Almeida, Diana K. C.,Listunov, Dymytrii,Joly, Etienne,Abderrahim, Raoudha,de Mattos, Marcos C.,de Oliveira, Maria C. F.,Maraval, Valérie,Chauvin, Remi,Génisson, Yves
, p. 1124 - 1130 (2018)
In line with a recent study of the pharmacological potential of bioinspired synthetic acetylenic lipids, after identification of the terminal dialkynylcarbinol (DAC) and butadiynyl alkynylcarbinol (BAC) moieties as functional antitumor pharmacophoric units, this work specifically addresses the issue of carbon backbone length. A systematic variation of the aliphatic chain length was thus carried out in both the DAC and BAC series. The critical impact of the length of the lipidic skeleton was first confirmed in the racemic series, with the highest cytotoxic activity observed for C17 to C18 backbones. Enantiomerically enriched samples were prepared by asymmetric synthesis of the optimal C18 DAC and C17 BAC derivatives. Samples with upgraded enantiomeric purity were alternatively produced by enzymatic kinetic resolution. Eutomers possessing the S configuration displayed cytotoxicity IC50 values as low as 15 nm against HCT116 cancer cells, the highest level of activity reached to date in this series.
Low-valent dialkoxytitanium(ii): a useful tool for the synthesis of functionalized seven-membered ring compounds
Bodinier, Florent,Sanogo, Youssouf,Ardisson, Janick,Lannou, Marie-Isabelle,Sorin, Geoffroy
supporting information, p. 3603 - 3606 (2021/04/14)
Herein, we describe unprecedented access to all-carbon or heterocyclic seven-membered ring frameworks from 1,8-ene-ynes promoted by inexpensive low-valent titanium(ii) species, readily available from Ti(OiPr)4and Grignard reagent. A broad range of cycloheptane, azepane or oxepane derivatives has been obtained (19 examples) with moderate to good yields and an excellent selectivity (up to 95/5 d.r.).
Ni-catalyzed direct carboxylation of propargylic alcohols with carbon dioxide
Yamahira, Tatsuya,Onodera, Gen,Fukuda, Tsutomu,Kimura, Masanari
supporting information, p. 853 - 855 (2021/05/19)
The carboxylation of propargylic alcohols containing a silyl group at the terminal position was conducted in a CO2 atmosphere at atmospheric pressure in the presence of a nickel catalyst and diethylzinc. Here, CO2 was used as not only the C1 source but also the promoter of the COH cleavage processes for the oxidative addition of propargylic alcohols.
Development of a Radical Silylzincation of (Het)Aryl-Substituted Alkynes and Computational Insights into the Origin of the trans-Stereoselectivity
Romain, Elise,de la Vega-Hernández, Karen,Guégan, Frédéric,Sanz García, Juan,Fopp, Carolin,Chemla, Fabrice,Ferreira, Franck,Gerard, Hélène,Jackowski, Olivier,Halbert, Stéphanie,Oestreich, Martin,Perez-Luna, Alejandro
supporting information, p. 2634 - 2647 (2021/03/30)
Aryl- and hetaryl-substituted acetylenes undergo regio- and stereoselective silylzincation by reaction with [(Me3Si)3Si]2Zn in the presence of Et2Zn (10–110 mol%) as additive. The distinctive feature of this addition across the C?C triple bond is its trans stereoselectivity. The radical nature of the silylzincation process is supported by diagnostic experiments and DFT calculations, which also corroborate the role played by steric effects to obtain that stereoselectivity. The procedure can be combined in one-pot with the copper(I)-mediated electrophilic substitution of the C(sp2)?Zn bond, with retention of the double bond geometry. This makes it valuable for the synthesis of stereodefined di- and trisubstituted vinylsilanes. (Figure presented.).
Catalytic Asymmetric Total Synthesis of Exiguolide
Oka, Kengo,Fuchi, Shunsuke,Komine, Keita,Fukuda, Hayato,Hatakeyama, Susumi,Ishihara, Jun
supporting information, p. 12862 - 12867 (2020/09/16)
The catalytic asymmetric total synthesis of (?)-exiguolide, a complex 20-membered macrolide embedded with a bis(tetrahydropyran) motif, is reported. The convergent synthesis involves the construction of the C1–C11 tetrahydropyran segment via catalytic asymmetric allylation and Prins cyclization, and the formation of the C12–C21 phosphonate segment via catalytic asymmetric cyclocondensation reaction and Johnson–Claisen rearrangement. The synthesis of 15-epi-exiguolide is also described.
Exploring the scope of tandem palladium and isothiourea relay catalysis for the synthesis of α-amino acid derivatives
Bitai, Jacqueline,Slawin, Alexandra M.Z.,Cordes, David B.,Smith, Andrew D.
supporting information, (2020/07/27)
The scope and limitations of a tandem N-allylation/[2,3]-rearrangement protocol are investigated through the incorporation of a variety of functional groups within an allylic phosphate precursor. This method uses readily accessible N,N-dimethylglycine aryl esters and functionalized allylic phosphates, forming quaternary ammonium salts in situ in the presence of a palladium catalyst. Subsequent enantioselective [2,3]-sigmatropic rearrangement, promoted by the chiral isothiourea tetramisole, generates α-amino acid derivatives with two contiguous stereocenters. The incorporation of electron-withdrawing ester and amide groups gave the best results, furnishing the desired products in moderate to good yields (29-70percent), with low diastereocontrol (typically 60:40 dr) but high enantioselectivity (up to 90:10 er). These results indicate that substrate-catalyst interactions in the proposed transition state are sensitive to the substitution pattern of the substrates.
